alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET CURRENT_EVENTS [Fireeye] Backdoor.HTTP.BEACON.[CSBundle Original Stager]"; flow:established,to_server; http.accept; content:"*/*"; startswith; http.accept_lang; content:"en-US"; startswith; http.accept_enc; content:"gzip, deflate"; startswith; http.cookie; content:"SIDCC=AN0-TYutOSq-fxZK6e4kagm70VyKACiG1susXcYRuxK08Y-rHysliq0LWklTqjtulAhQOPH8uA"; startswith; fast_pattern; http.uri; content:"/api/v1/user/"; content:"/avatar/"; distance:3; within:8; pcre:"/\/api\/v1\/user\/(?:512|124)\/avatar/"; reference:url,github.com/fireeye/red_team_tool_countermeasures; classtype:trojan-activity; sid:2031277; rev:5; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2020_12_08, deployment Perimeter, confidence High, signature_severity Major, tag c2, updated_at 2024_04_13, mitre_tactic_id TA0010, mitre_tactic_name Exfiltration, mitre_technique_id T1041, mitre_technique_name Exfiltration_Over_C2_Channel;)